The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A050155 Triangle T(n,k), k>=0 and n>=1, read by rows defined by: T(n,k) = (2k+3)*binomial(2n,n-k-1)/(n+k+2). 4
 1, 3, 1, 9, 5, 1, 28, 20, 7, 1, 90, 75, 35, 9, 1, 297, 275, 154, 54, 11, 1, 1001, 1001, 637, 273, 77, 13, 1, 3432, 3640, 2548, 1260, 440, 104, 15, 1, 11934, 13260, 9996, 5508, 2244, 663, 135, 17, 1, 41990, 48450, 38760, 23256, 10659, 3705, 950, 170, 19, 1 (list; table; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS T(n-2k-1,k) = number of n-th generation vertices in the tree of sequences with unit increase labeled by 2k+2 (cf. Zoran Sunic reference) . - Benoit Cloitre, Oct 07 2003 Number of lattice paths from (0,0) to (n,n) with steps E=(1,0) and N=(0,1) which touch but do not cross the line x-y=k+1 . - Herbert Kociemba, May 24 2004 Number of standard tableaux of shape (n+k+1, n-k-1). - Emeric Deutsch, May 30 2004 Riordan array (c(x)^3,xc(x)^2) where c(x) is the g.f. of A000108. Inverse array is A109954. - Paul Barry, Jul 06 2005 LINKS Alois P. Heinz, Rows n = 1..141, flattened R. K. Guy, Catwalks, Sansteps and Pascal Pyramids, J. Integer Seq., Vol. 3 (2000), #00.1.6 V. E. Hoggatt, Jr. and M. Bicknell, Catalan and related sequences arising from inverses of Pascal's triangle matrices, Fib. Quart., 14 (1976), 395-405. A. Papoulis, A new method of inversion of the Laplace transform, Quart. Appl. Math 14 (1957), 405-414. J. Riordan, The distribution of crossings of chords joining pairs of 2n points on a circle, Math. Comp., 29 (1975), 215-222. _Zoran Sunic_, Self-Describing Sequences and the Catalan Family Tree, Electronic Journal of Combinatorics, 10 (2003) #N5. FORMULA Sum_{ k = 0, .., n-1} T(n, k) = binomial(2n, n-1) = A001791(n). For the column k : expansion of x^(k+1)C^(2k+3) where C = (1-(1-4*x)^(1/2)/(2*x) is the g.f. of Catalan numbers A000108. - Philippe Deléham, Feb 03 2004 T(n, k) = A039599(n, k+1) = A009766(n+k+1, n-k-1) = A033184(n+k+2, 2k+3) . - Philippe Deléham, May 28 2005 Sum_{k>= 0} T(m, k)*T(n, k) = A000108(m+n) - A000108(m)*A000108(n). - Philippe Deléham, May 28 2005 T(n, k)=(2k+3)binomial(2n+2, n+k+2)/(n+k+3)=C(2n+2, n+k+2)-C(2n+2, n+k+3) [offset (0, 0)]. - Paul Barry, Jul 06 2005 EXAMPLE 1; 3, 1; 9, 5, 1; 28, 20, 7, 1; 90, 75, 35, 9, 1; 297, 275, 154, 54, 11, 1; . . . MAPLE T:= (n, k)->  (2*k+3)*binomial(2*n, n-k-1)/(n+k+2): seq(seq(T(n, k), k=0..n-1), n=1..10);  # Alois P. Heinz, Jan 19 2013 MATHEMATICA T[n_, k_] :=  (2*k + 3)*Binomial[2*n, n - k - 1]/(n + k + 2); Table[T[n, k], {n, 1, 10}, {k, 0, n - 1}] // Flatten (* Jean-François Alcover, May 21 2016 *) CROSSREFS First columns: A000245, A000344, A000588, A001392, A000589, A000590. Cf. A000108, A001791 (row sums), A050144. Sequence in context: A005533 A331257 A112626 * A270236 A140714 A112932 Adjacent sequences:  A050152 A050153 A050154 * A050156 A050157 A050158 KEYWORD nonn,tabl AUTHOR EXTENSIONS Edited by Philippe Deléham, May 22 2005 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified June 25 00:34 EDT 2021. Contains 345445 sequences. (Running on oeis4.)